Bucket loaders, such as LHDs, are vehicles having buckets at their front end, which are usually operated by hydraulic actuators or cylinders and which are used to load bulk material, such as rock, into the bucket and transport or haul the same to an unloading area where the material is dumped from the bucket. Normally such loaders are operated by skilled operators who control the many different operations of the working cycle of the vehicle. While sitting in the operator's cabin of the machine the operator can see and "feel" the reaction of the machine when filling the bucket. It is also possible to operate such loaders under computer control from a distance using a remote control device working with radio signals. However, any such operation usually proceeds according to a pre-programmed or predetermined loading cycle and cannot adjust the loader in response to some particular conditions, such as encountering an oversize rock or the like.
Attempts have also been made to tele-operate the loader by installing a TV camera on the vehicle and observing the pile of material to be loaded through such camera while loading the bucket. Such an operation is described by D. Kumar and Nick Vagenas in an article entitled "Performance evaluation of an automatic load-haul dump vehicle" published in the CIM Bulletin, Volume 86, No. 974, pp 39-42, October 1993. This operation cannot be considered as truly automatic since it still requires an operator positioned at a remote location to view the pile of material to be loaded through the TV camera and to operate the loader accordingly. The loader itself does not react automatically to the various loading conditions that may be encountered during such loading operation. In this instance the operator loses all "feeling" of the machine and must rely completely on his sense of vision to interpret the effectiveness of the vehicle's performance. Such vehicles are, therefore, subject to more abuse and usually require more maintenance.
It should be mentioned that when performing the loading cycle there are two objectives to be met: (1) obtaining an efficient loading of the bucket, which should be as full as possible each time the loading takes place, and (2) minimizing the abuse of the vehicle which increases the cost of vehicle maintenance and vehicle down time and thus significantly affects overall productivity.